Automatic system for guided acquistion of telephone line speech signals

Abstract: The invention relates to an automatic system for guided acquisition of speech signals from a telephone line. By automating the acquisition process of speech signals under control of a unique intelligent control unit, the work of the telephone operator is made very easier.

Description: The present invention relates to an automatic system for guided acquisition of telephone line speech signals. In the field of the speech processing, in particular of the automatic recognition, it is very important to have high-quality databases available. The generation of such databases occurs through long and repeated recording operations, often carried out in the same conditions as recognition will have to take place later on. In general a team of speakers is chosen and each speaker utters at least once the speech elements corresponding to a predetermined vocabulary (generally words or, less frequently, syllables); the speech signals corresponding to such utterances are acquired and recorded, often on special recorders called DAT (Digital Audio Tape). From US patent No. 5,125,022 a method for recognizing alphanumeric strings is disclosed, that comprises a processing system with a processor, an interface to telephone network and a database for storing a predetermined set of alphanumeric strings. In operation the system prompts the caller to speak characters of a string. Such a method has a very limited application, since it is intended to detect a code entry, so that that acts only on single characters. Such recognition be realized on speech signals from telephone lines, a method of getting the speakers to utter such speech elements consists in calling a telephone subscriber up and asking him to utter the words that an operator utters in advance one at a time. The object of the present invention is to take such recording operation easier. This object is achieved through the automatic system for guided acquisition of telephone line speech signals as set forth in claim 1; further advantageous aspects of the present invention are set forth in the subclaims. By automating the acquisition process under control of a unique control unit the work of the operator is made extremely easier. The present invention will result better from the following description taken in conjunction with the sole attached drawing that represents a conceptual block diagram of the invention. The automatic system for guided acquisition of speech signals from a telephone line TR, in accordance with the present invention, comprises: a) first storage means M1 designed to contain a plurality of operator speech messages and provided with a message output and with a control input for the selection and emission of the speech messages from said output, b) second storage means M2 designed to store a plurality of user speech signals and provided with a signal input and a control input for storing speech signals, c) a telephone interface INT electrically connected with the telephone line TR, receiving at its input speech messages from said first speech message storage means M1, outputting speech signals to said second storage means M2 and having a control input for establishing ringings, and d) a control unit CU connected with said control inputs and designed to control the operation of the system. For clarity, the operator speech messages are substantially the words of the vocabulary that the user will have to utter. Clearly, there are in practice several possibilities of realizing the various components of the system just listed. All the system could be, e.g., realized by only one personal computer equipped with a signal acquisition, generation and digital processing card; or by a personal computer suitably interfaced with a DAT (Digital Audio Tape) recorder. An automatic speech synthesizer SY can be connected with the message output of the storage means M1; in this circumstance the plurality of operator speech messages will be stored into means M1 in a textual form. In a more simple case, in which there is not the synthesizer SY, the plurality of operator speech messages can be advantageously stored in the form of a plurality of synthetic speech signals. It may be useful that an operator TL is electrically connected with the telephone interface INT to allow the operator to talk with the called user before starting the acquisition of the speech signals; in addition, such telephone TL may also be used for establishing calls. If there is a telephone TL, the control input of the telephone interface INT is further designed to control the connection of the telephone line TR to the telephone itself, for instance in order to disable it during acquisition. If the telephone TL is not provided with a device for establishing ringings or, anyway, if it is preferred not to use it, it may be contemplated that the control unit CU provides the telephone interface INT with information about the user to be called up: the dial signallings or tones to be sent directly over the telephone line TR; this can be particularly advantageous if the system has to work in a totally autonomous manner without the intervention of an operator; then it will be useful to provide the unit CU with a list of telephone numbers of users to be called up. For reporting to control unit CU the start and the end of acquisition operations it may be contemplated, e.g., to use a push-button BT connected with the unit itself; in many cases unit CU will be provided with several push-buttons for carrying out other functions. Only speech signals from the called user can be stored in sequence into storage means M2 or, for a more simple realization, it can be seen that storage means M2 are capable of storing all speech signals of a ringing. Interface INT can be, e.g., formed by a two-to-four wire telephone converter HY and by a controlled switch SW. Converter HY is electrically connected, from the four-wire side, at the input, with means M1 or with synthesizer SY depending on the circumstances, and at the output, with means M2, and from the two-wire side, with switch SW; switch SW receives at its input the two-wire telephone line TR and connects it to converter HY or to telephone TL, depending on the control signals from unit CU. The operation of the system in accordance with the present invention will now be described. Depending on the control unit CU used, the operation can be a little different. In a very simple case, after having established a ringing, an operator, through the telephone TL, explains the situation to the called user and then starts acquisition through push-button BT. Unit CU detects pressure of push-button BT and at the same time transmits: a control signal to means M1 to start utterance of the vocabulary words, one at a time and in a suitably broken manner to give the called user time to repeat them, a control signal to means M2 to start storing, and a control signal to interface INT to disconnect line TR from the telephone TL and connect it, e.g. through converter HY, with means M1 and M2. In this case, means M2 store both speech signals corresponding to speech messages stored into means M1 and speech signals emitted by the called user. The fact that the called user receives operator messages, i.e. the words of the vocabulary, synthetic and hence unnatural, is advantageous because the copy effect of the original operator message prosody will be avoided. In a more complicated case, the operator provides in advance the unit CU with a list of telephone subscribers to be called up for acquisition, and also stores at least one performance speech message into means M1 and then starts the acquisition. Unit CU sends dial signalling to interface INT for establishing a ringing with the first telephone subscriber of the list and the latter (INT) in turn sends them over the line TR; as soon as the subscriber lifts the handset, unit CU sends the performance speech message from means M1 to interface INT which in turn sends it over line TR; if the subscriber replaces the handset, thus indicating its unwillingness to cooperate, the acquisition process goes on with the second subscriber in the list; unit CU then checks the sending of the first word of the vocabulary and, as soon as the synthetic utterance of the same is terminated, it activates means M2 for storing the corresponding utterance of the subscriber. Such operations are repeated for all the words of the vocabulary and for all the listed subscribers. Naturally the above description both of the system and of its operation is given by way of an example only and several variants can be found by those skilled in the art.

Claims: Automatic system for guided acquisition from a telephone line (TR) of speech signals, corresponding to a predetermined vocabulary to be used in speech recognition databases, comprising: a) first storage means (M1) designed to contain a plurality of operator speech messages, said messages asking called telephone subscribers to utter elements of said predetermined vocabulary, and provided with a message output and a control input for the selection and the emission of speech message from said output, b) second storage means (M2) designed to store a plurality of user speech signals, recorded from the subscriber's answer utterances to said messages, and provided with a signal input and a control input for storing speech signals, c) a telephone interface (INT) electrically connected to said telephone-line (TR), receiving at its input speech messages from said first storage means (M1), outputting speech signals to said second storage means (M2), and having a control input for establishing calls to said subscribers, and d) a control unit (CU) connected with said control inputs and designed to control the operation of the system. System according to claim 1, characterized in that said plurality of operator speech messages is stored into said first storage means (M1) in the form of a plurality of synthetic speech signals, and said message output of said first storage means (M1) is connected to an automatic speech synthesizer (SY). System according to claim 1, characterized in that said telephone interface (INT) is electrically connected with an operator telephone (TL) and in that said control input of said telephone interface (INT) is further designed to control the connection of said telephone line (TR) with said operator line (TL). System according to claim 1, characterized in that said control unit (CU) transmits to said telephone interface (INT) information about the subscribers to be called. System according to claim 1, characterized in that said second storage means (M2) are designed to store all the speech signals obtained from said calls.

Inventors: DE SANTIS GERARDO, RICCIO ANTONELLO, RIGOSI FRANCESCA, DE SANTIS, GERARDO, RICCIO, ANTONELLO, RIGOSI, FRANCESCA
Applicants: CIT ALCATEL, ALCATEL
Application year: 1994
Main classification: G10L15
IPC codes: H04M3